Numerical analysis of seabed dynamic response around side-by-side twin-pile group under wave-current interaction

This study investigates seabed dynamic responses around side-by-side twin piles under various wave-current combinations using a 3D numerical model with integrating wave-current-structure-seabed interaction (WCSSI). The analysis, based on a finite volume method (FVM) framework within OpenFOAM, examines wave elevation, dynamic pressure, flow velocity, pore pressure attenuation, and liquefaction characteristics. Results show that following currents increase wave elevation at pile centres and wave-facing sides while reducing lateral wave elevation, whereas opposing currents exhibit the opposite trend. Flow velocity at pile centres increases with following currents but decreases under opposing conditions. Wave pressure attenuation is more pronounced under opposing currents. Pore pressure correlates positively with the following current intensity at wave-facing and leeward sides, but negatively under opposing currents. The liquefaction depth is greater at interior sides than at lateral side, with opposing currents inducing greater liquefaction depth than following currents. Leeward liquefaction intensifies with stronger following currents but diminishes under opposing conditions, while less liquefaction occurs at wave-facing sides.